Lennox SL280DFV User Manual

INSTALLATION

 2011 Lennox Industries Inc.

Dallas, Texas, USA

DOWNFLOW

INSTRUCTIONS SL280DFV

DAVE LENNOX SIGNATURE COLLECTION GAS FURNACE DOWNFLOW AIR DISCHARGE

506710−01 06/2011 Supersedes 01/2011

THIS MANUAL MUST BE LEFT WITH THE

HOMEOWNER FOR FUTURE REFERENCE

WARNING

Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury or loss of life. Installation and service must be performed by a licensed professional installer (or equivalent), service agency or the gas supplier.

Litho U.S.A.

AIR FLOW

CAUTION

As with any mechanical equipment, personal injury can result from contact with sharp sheet metal edges. Be careful when you handle this equipment.

This is a safety alert symbol and should never be ignored. When you see this symbol on labels or in manuals, be alert to the potential for personal injury or death.

Table of Contents

Unit Dimensions 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Parts Arrangement 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SL280DFV Gas Furnace 4. . . . . . . . . . . . . . . . . . . . . . . . .

Shipping and Packing List 4. . . . . . . . . . . . . . . . . . . . . . . .

Safety Information 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Use of Furnace as a Construction Heater 5. . . . . . . . . . .

General 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Combustion, Dilution & Ventilation Air 6. . . . . . . . . . . . . .

Setting Equipment 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Filters 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Duct System 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Venting 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Gas Piping 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

06/11

*2P0611*

Page 1

NOTICE

A thermostat is not included and must be ordered separately.

 The Lennox icomfort Touch thermostat must be

used in communicating applications.

 In non−communicating applications, the Lennox

ComfortSense well as other non−communicating thermostats.

In all cases, setup is critical to ensure proper system operation.

Field wiring for both communicating and non−communicating applications is illustrated in diagrams, which begin on Page 23.

Electrical 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Integrated Control Settings 32. . . . . . . . . . . . . . . . . . . . . . .

Blower Performance Data 35. . . . . . . . . . . . . . . . . . . . . . . .

Unit Start−Up 39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Gas Pressure Adjustment 40. . . . . . . . . . . . . . . . . . . . . . . .

Proper Combustion 40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

High Altitude 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Other Unit Adjustments 42. . . . . . . . . . . . . . . . . . . . . . . . . .

Heating Sequence of Operation 42. . . . . . . . . . . . . . . . . . .

Service 44. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Planned Service 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Repair Parts List 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Integrated Control Diagnostic Codes 48. . . . . . . . . . . . . . .

Program Unit Capacity/Size Mode 55. . . . . . . . . . . . . . . . .

Troubleshooting 56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7000 thermostat may be used, as

506710−01

*P506710-01*

Unit Dimensions − inches (mm)

3−1/8

(79)

9/16

(14)

RETURN AIR

OPENING

FLUE OUTLET

(Top)

19−7/16

9/16

(14)

(494)

9/16

(14)

TOP VIEW

9/16

(14)

1−1/2 (38) Front Panel

27−3/4 (7705)

19−7/16

(494)

9/16

(14)

ELECTRICAL INLET

(Either Side)

GAS PIPING INLET

(Either Side)

19−1/4

Supply

(489)

Air

Supply

Air

(838)

5−3/8 (137) Right 2−1/8 (54) Left

6−5/8 (168) Right 7−1/8 (181) Left

3/4

(19)

FRONT VIEW SIDE VIEW

Model No.

SL280DF070V36A 14−1/2 368 13−3/8 340 13 330 4−3/4 121 SL280DF090V48B

SL280DF090V60C SL280DF110V60C

17−1/2 446 16−3/8 416 16 406 6−1/4 159

A B C D

in. mm in. mm in. mm in. mm

21 533 19−7/8 504 19−1/2 495 8 203

Page 2

Parts Arrangement

CONTROL BOX

(Includes two−stage integrated control,

transformer and circuit breaker)

INTERNAL FLUE PIPE ASSEMBLY

GASKET

FLUE CHASE

BLOWER ASSEMBLY

SECONDARY LIMIT

DOOR INTERLOCK SWITCH

ROLLOUT SWITCH

INNER BLOWER ACCESS PANEL

ACCESS PANEL

PRIMARY LIMIT LOCATION

HEAT EXCHANGER

COMBUSTION AIR INDUCER

PRESSURE SWITCHES

COMBUSTION AIR INDUCER

GAS VALVE

BURNER BOX ASSEMBLY

FIGURE 1

Page 3

SL280DFV Gas Furnace

The SL280DFV gas furnace is equipped with a two−stage, variable speed integrated control. the control is compatible with: Communicating thermostats − icomfort Touch Non−communicating thermostats − ComfortSense or other conventional thermostats. Control systems − Harmony III Zone Control System (non−communicating). Each SL280DFV unit is shipped ready for installation in the downflow position.

Shipping and Packing List

Package 1 of 1 contains

1 − Assembled SL280DFV unit 1 − Bag assembly containing the following:

2 − Screws 1 − Snap bushing 1 − Snap plug 1 − Wire tie 1 − Vent warning label 1 − Owner’s manual and warranty card

The following items may be ordered separately: 1 − Thermostat 1 − Propane/LP changeover kit 1 − Combustible flooring base

Check equipment for shipping damage. If you find any damage, immediately contact the last carrier.

Safety Information

DANGER

Danger of explosion.

There are circumstances in which odorant used with LP/propane gas can lose its scent. In case of a leak, LP/propane gas will settle close to the floor and may be difficult to smell. An LP/propane leak detector should be installed in all LP applications.

WARNING

CAUTION

As with any mechanical equipment, personal injury can result from contact with sharp sheet metal edges. Be careful when you handle this equipment.

Certifications

SL280DFV units are CSA International certified.

In the USA, installation of gas furnaces must conform with local building codes. In the absence of local codes, units must be installed according to the current National Fuel Gas Code (ANSI-Z223.1). The National Fuel Gas Code is available from the following address:

American National Standards Institute, Inc. 11 West 42nd Street New York, NY 10036

Clearances

Adequate clearance must be made around the air openings into the vestibule area. In order to ensure proper unit operation, combustion and ventilation air supply must be provided according to the current National Fuel Gas Code.

Vent installations must be consistent with the venting tables (in this instruction) and applicable provisions of local building codes.

This furnace is CSA International certified for installation clearances to combustible material as listed on the unit nameplate and in the tables in figure 13. Accessibility and service clearances must take precedence over fire protection clearances.

Installed Locations

For installation in a residential garage, the furnace must be installed so that the burner(s) and the ignition source are located no less than 18 inches (457 mm) above the floor. The furnace must be located or protected to avoid physical damage by vehicles. When a furnace is installed in a public garage, hangar, or other building that has a hazardous atmosphere, the furnace must be installed according to recommended good practice requirements and current National Fuel Gas Code.

NOTE − Furnace must be adjusted to obtain a temperature rise (high and low fire) within the range(s) specified on the unit nameplate. Failure to do so may cause erratic limit operation and may also result in premature heat exchanger failure.

This SL280DFV furnace must be installed so that its electrical components are protected from water.

Installed in Combination with a Cooling Coil

When this furnace is used with cooling units, it shall be installed in parallel with, or on the upstream side of, cooling units to avoid condensation in the heating compartment. With a parallel flow arrangement, a damper (or other means to control the flow of air) must adequately prevent

Page 4

chilled air from entering the furnace (see figure 1). If the damper is manually operated, it must be equipped to prevent operation of either the heating or the cooling unit, unless it is in the full HEAT or COOL setting.

GAS UNIT

Dampers

(open during heating

operation only)

AIR HANDLER

Dampers

(open during cooling

operation only)

FIGURE 1

When installed, this furnace must be electrically grounded according to local codes. In addition, in the United States, installation must conform with the current National Electric Code, ANSI/NFPA No. 70. The National Electric Code (ANSI/NFPA No. 70) is available from the following address:

National Fire Protection Association 1 Battery March Park Quincy, MA 02269

NOTE − This furnace is designed for a minimum continuous return air temperature of 60°F (16°C) or an intermittent operation down to 55°F (13°C) dry bulb for cases where a night setback thermostat is used. Return air temperature must not exceed 85°F (29°C) dry bulb.

The SL280DFV furnace may be installed in alcoves, closets, attics, basements, garages, and utility rooms in the downflow position.

This furnace design has not been CSA International certified for installation in mobile homes, recreational vehicles, or outdoors.

Use of Furnace as Construction Heater

Lennox does not recommend the use of SL280DFV units as a construction heater during any phase of construction. Very low return air temperatures, harmful vapors and operation of the unit with clogged or misplaced filters will damage the unit.

SL280DFV units may be used for heating of buildings or structures under construction, if the following conditions are met:

D The vent system must be permanently installed per

these installation instructions.

D A room thermostat must control the furnace. The use of

fixed jumpers that will provide continuous heating is not allowed.

D The return air duct must be provided and sealed to the

furnace.

D Return air temperature range between 60°F (16°C) and

80°F (27°C) must be maintained.

D Air filters must be installed in the system and must be

maintained during construction.

D Air filters must be replaced upon construction comple-

tion.

D The input rate and temperature rise must be set per the

furnace rating plate.

D One hundred percent (100%) outdoor air must be pro-

vided for combustion air requirements during construction. Temporary ducting may supply outdoor air to the furnace. Do not connect duct directly to the furnace. Size the temporary duct following these instructions in section for Combustion, Dilution and Ventilation Air in a confined space with air from outside.

D The furnace heat exchanger, components, duct system,

air filters and evaporator coils must be thoroughly cleaned following final construction clean−up.

D All furnace operating conditions (including ignition, in-

put rate, temperature rise and venting) must be verified according to these installation instructions.

General

These instructions are intended as a general guide and do not supersede local codes in any way. Consult authorities having jurisdiction before installation.

In addition to the requirements outlined previously, the following general recommendations must be considered when installing a SL280DFV furnace:

 Place the furnace as close to the center of the air dis-

tribution system as possible. The furnace should also be located close to the chimney or vent termination point.

 Do not install the furnace where drafts might blow direct-

ly into it. This could cause improper combustion and unsafe operation.

 Do not block the furnace combustion air openings with

clothing, boxes, doors, etc. Air is needed for proper combustion and safe unit operation.

 When the furnace is installed in an attic or other insu-

lated space, keep insulation away from the furnace.

NOTE − The Commonwealth of Massachusetts stipulates these additional requirements:

D Gas furnaces shall be installed by a licensed plumb-

er or fitter only.

Page 5

D The gas cock must be T handle" type.

D When a furnace is installed in an attic, the passage-

way to and service area surrounding the equipment shall be floored.

WARNING

Product contains fiberglass wool.

Disturbing the insulation in this product during installation, maintenance, or repair will expose you to fiberglass wool. Breathing this may cause lung cancer. (Fiberglass wool is known to the State of California to cause cancer.)

Fiberglass wool may also cause respiratory, skin, and eye irritation.

To reduce exposure to this substance or for further information, consult material safety data sheets available from address shown below, or contact your supervisor.

Lennox Industries Inc. P.O. Box 799900 Dallas, TX 75379−9900

Combustion, Dilution & Ventilation Air

In the past, there was no problem in bringing in sufficient outdoor air for combustion. Infiltration provided all the air that was needed. In today’s homes, tight construction practices make it necessary to bring in air from outside for combustion. Take into account that exhaust fans, appliance vents, chimneys, and fireplaces force additional air that could be used for combustion out of the house. Unless outside air is brought into the house for combustion, negative pressure (outside pressure is greater than inside pressure) will build to the point that a downdraft can occur in the furnace vent pipe or chimney. As a result, combustion gases enter the living space creating a potentially dangerous situation.

In the absence of local codes concerning air for combustion and ventilation, use the guidelines and procedures in this section to install SL280DFV furnaces to ensure efficient and safe operation. You must consider combustion air needs and requirements for exhaust vents. A portion of this information has been reprinted with permission from the National Fuel Gas Code (ANSI-Z223.1). This reprinted material is not the complete and official position of the ANSI on the referenced subject, which is represented only by the standard in its entirety.

CAUTION

Do not install the furnace in a corrosive or contaminated atmosphere. Meet all combustion and ventilation air requirements, as well as all local codes.

CAUTION

Insufficient combustion air can cause headaches, nausea, dizziness or asphyxiation. It will also cause excess water in the heat exchanger resulting in rusting and premature heat exchanger failure. Excessive exposure to contaminated combustion air will result in safety and performance related problems. Avoid exposure to the following substances in the combustion air supply:

Permanent wave solutions Chlorinated waxes and cleaners Chlorine base swimming pool chemicals Water softening chemicals De-icing salts or chemicals Carbon tetrachloride Halogen type refrigerants Cleaning solvents (such as perchloroethylene) Printing inks, paint removers, varnishes, etc. Hydrochloric acid Cements and glues Antistatic fabric softeners for clothes dryers Masonry acid washing materials

All gas-fired appliances require air for the combustion process. If sufficient combustion air is not available, the furnace or other appliances will operate inefficiently and unsafely. Enough air must be provided to meet the needs of all fuel-burning appliances and appliances such as exhaust fans which force air out of the house. When fireplaces, exhaust fans, or clothes dryers are used at the same time as the furnace, much more air is necessary to ensure proper combustion and to prevent a downdraft. Insufficient air causes incomplete combustion which can result in carbon monoxide.

In addition to providing combustion air, fresh outdoor air dilutes contaminants in the indoor air. These contaminants may include bleaches, adhesives, detergents, solvents and other contaminants which can corrode furnace components.

The requirements for providing air for combustion and ventilation depend largely on whether the furnace is installed in an unconfined or a confined space.

Unconfined Space

An unconfined space is an area such as a basement or large equipment room with a volume greater than 50 cubic feet (1.42 m bined input rating of all appliances installed in that space. This space also includes adjacent rooms which are not separated by a door. Though an area may appear to be unconfined, it might be necessary to bring in outdoor air for combustion if the structure does not provide enough air by infiltration. If the furnace is located in a building of tight construction with weather stripping and caulking around the windows and doors, follow the procedures in the air from outside section.

) per 1,000 Btu (.29 kW) per hour of the com-

Page 6

Confined Space

A confined space is an area with a volume less than 50 cubic feet (1.42 m

) per 1,000 Btu (.29 kW) per hour of the combined input rating of all appliances installed in that space. This definition includes furnace closets or small equipment rooms.

When the furnace is installed so that supply ducts carry air circulated by the furnace to areas outside the space containing the furnace, the return air must be handled by ducts which are sealed to the furnace casing and which terminate outside the space containing the furnace. This is especially important when the furnace is mounted on a platform in a confined space such as a closet or small equipment room. Even a small leak around the base of the unit at the platform or at the return air duct connection can cause a potentially dangerous negative pressure condition. Air for combustion and ventilation can be brought into the confined space either from inside the building or from outside.

EQUIPMENT IN CONFINED

CHIMNEY

OR GAS

VENT

FURNACE

NOTE − Each opening shall have a free area of at least one square inch (645 mm ing of all equipment in the enclosure, but not less than 100 square inches (64516 mm

) per 1,000 Btu (.29 kW) per hour of the total input rat-

SPACE ALL AIR FROM INSIDE

WATER

HEATER

OPENINGS

(To Adjacent

Room)

FIGURE 2

Air from Inside

If the confined space that houses the furnace adjoins a space categorized as unconfined, air can be brought in by providing two permanent openings between the two spaces. Each opening must have a minimum free area of 1 square inch (645 mm

) per 1,000 Btu (.29 kW) per hour of total input rating of all gas−fired equipment in the confined space. Each opening must be at least 100 square inches (64516 mm

). One opening shall be within 12 inches (305 mm) of the top of the enclosure and one opening within 12 inches (305 mm) of the bottom. See figure 2.

Air from Outside

If air from outside is brought in for combustion and ventilation, the confined space must have two permanent openings. One opening shall be within 12 inches (305 mm) of the top of the enclosure and one opening within 12 inches (305 mm) of the bottom. These openings must communicate directly or by ducts with the outdoors or spaces (crawl or attic) that freely communicate with the outdoors or indirectly through vertical ducts. Each opening shall have a minimum free area of 1 square inch (645 mm

) per 4,000 Btu (1.17

kW) per hour of total input rating of all equipment in the enclosure. See figures 3 and 4. When communicating with the outdoors through horizontal ducts, each opening shall have a minimum free area of 1 square inch (645 mm

) per

2,000 Btu (.56 kW) per total input rating of all equipment in the enclosure. See figure 5.

When ducts are used, they shall be of the same cross−sectional area as the free area of the openings to which they connect. The minimum dimension of rectangular air ducts shall be no less than 3 inches (75 mm). In calculating free area, the blocking effect of louvers, grilles, or screens must be considered. If the design and free area of protective covering is not known for calculating the size opening required, it may be assumed that wood louvers will have 20 to 25 percent free area and metal louvers and grilles will have 60 to 75 percent free area. Louvers and grilles must be fixed in the open position or interlocked with the equipment so that they are opened automatically during equipment operation.

Page 7

CHIMNEY OR

GAS VENT

FURNACE

(Inlet Air from Crawlspace and Outlet Air to Ventilated Attic)

VENTILATION LOUVERS

(Each end of attic)

EQUIPMENT IN CONFINED SPACE

ALL AIR FROM OUTSIDE

OUTLET

AIR

WATER

HEATER

CHIMNEY

OR GAS

VENT

FURNACE

VENTILATION

LOUVERS

(For unheated crawl space)

NOTE−The inlet and outlet air openings shall each have a free area of at least one square inch (645

) per 4,000 Btu (1.17 kW) per hour of the total input rating of all equipment in the enclosure.

INLET

AIR

FIGURE 3

EQUIPMENT IN CONFINED SPACE

ALL AIR FROM OUTSIDE

(All Air Through Ventilated Attic)

VENTILATION LOUVERS

(Each end of attic)

OUTLET

AIR

INLET AIR

(Ends 12 in.

above bottom)

FURNACE

CHIMNEY

OR GAS

VENT

CONFINED SPACE

WATER

HEATER

OUTLET AIR

INLET AIR

EQUIPMENT IN

ALL AIR FROM

OUTSIDE

WATER

HEATER

NOTE−The inlet and outlet air openings shall each have a free area of at least one square inch (645 mm

) per 4,000 Btu (1.17 kW) per hour of the total input rating of all equipment in the enclosure.

FIGURE 4

Page 8

NOTE − Each air duct opening shall have a free area of at least one square inch (645 mm

) per 2,000 Btu (.59 kW) per hour of the total input rating of all equipment in the enclosure. If the equipment room is located against an outside wall and the air openings communicate directly with the outdoors, each opening shall have a free area of at least one square inch (645 mm per 4,000 Btu (1.17 kW) per hour of the total input rating of all other equipment in the enclosure.

FIGURE 5

)

Downflow Installation

Downflow unit installs in three ways: on non−combustible flooring, on combustible flooring using a downflow combustible flooring base, or on a reverse−flow cooling cabinet. Do not drag the unit across the floor.

Installation on Non−Combustible Flooring (Figure 6)

CAUTION

The furnace and downflow combustible flooring base shall not be installed directly on carpeting, tile, or other combustible material other than wood flooring.

1 − Cut floor opening keeping in mind clearances listed on

unit rating plate. Also keep in mind gas supply connections, electrical supply, flue and air intake connections and sufficient installation and servicing clearances. See table 1 for correct floor opening size.

2 − Flange warm air plenum and lower the plenum into the

opening.

3 − Set the unit over the plenum and seal the plenum to

the unit.

4 − Ensure that the seal is adequate.

SL280DFV UNIT

OPENING

SUPPLY AIR

PLENUM

SL280DFV UNIT

SUPPLY AIR PLENUM

PROPERLY

SIZED FLOOR

OPENING

DOWNFLOW

COMBUSTIBLE

FLOORING BASE

FIGURE 7

TABLE 2

COMBUSTIBLE FLOOR OPENING SIZE

Cabinet Width

A (14.5")

B (17.5")

C (21")

NOTE − Floor opening dimensions listed are 1/4 inch (6 mm) larger than unit opening. See unit dimensions on page 2.

Front to Rear Side to Side

in. mm in. mm

22 559 15−3/4 400

22 559 18−3/4 476

22 559 22−3/4 578

FIGURE 6

TABLE 1

NON−COMBUSTIBLE FLOOR OPENING SIZE

Cabinet Width

A (14.5") 19−3/4 502 13−1/4 337

B (17.5") 19−3/4 502 16−1/4 413

C (21") 19−3/4 502 19−3/4 502

NOTE − Door opening dimensions listed are 1/4 inch (6 mm) larger than the unit opening. See unit dimensions on page 2.

Front to Rear Side to Side

in. mm in. mm

Installation on Combustible Flooring (Figure 7)

1 − When unit is installed on a combustible floor, a down-

flow combustible flooring base must be installed between the furnace and the floor. The base must be ordered separately.

See table 2 for opening size to cut in floor.

2 − After opening is cut, set combustible flooring base into

opening.

3 − Check sealing strips on combustible flooring base to

make sure they are properly glued and positioned.

4 − Lower supply air plenum into downflow combustible

flooring base until plenum flanges seal against the strips.

NOTE − Be careful not to damage sealing strips. Check for a tight seal.

5 − Set the furnace over the plenum.

6 − Ensure that the seal between the furnace and plenum

is adequate.

Installation on Cooling Cabinet (Figure 8)

1 − Refer to reverse−flow coil installation instructions for

correctly sized opening in floor and installation of cabinet.

NOTE − Downflow combustible flooring kit is not used

2 − When cooling cabinet is in place, set and secure the

furnace according to the instructions that are provided with the cooling coil. Secure the furnace to the cabinet.

3 − Seal the cabinet and check for air leaks.

Page 9

PROPERLY

SIZED FLOOR

OPENING

SL280DFV UNIT

COOLING COIL

PLENUM

Setting Equipment

WARNING

Do not install the furnace on its front, back or in the horizontal position. See figure 12. Do not connect the return air ducts to the back of the furnace. Doing so will adversely affect the operation of the safety control devices, which could result in personal injury or death.

Install the SL280DFV gas furnace as shipped in the downflow position only. Do not install the furnace hori-

zontally.

FIGURE 8

Return Air Opening −− Downflow Units

The following steps should be taken when installing plenum:

1 − Bottom edge of plenum should be flanged with a

hemmed edge (See figure 9).

PLENUM

SECURE FROM

OUTSIDE CABINET

Side View

HEMMED EDGE

SEALING STRIP

(Field Provided)

CABINET SIDE PANEL

FIGURE 9

2 − Sealing strip should be used.

3 − In all cases, plenum should be secured to top flanges

of furnace with sheet metal screws.

SECURE FROM IN-

SIDE CABINET

PLENUM

Side View

HEMMED EDGE

Select a location that allows for the required clearances that are listed on the unit nameplate. Also consider gas supply connections, electrical supply, vent connection, and installation and service clearances [24 inches (610 mm) at unit front]. The unit must be level.

NOTE − Units with 1/2 hp blower motors are equipped with three flexible legs and one rigid leg. See figure 11. The rigid leg is equipped with a shipping bolt and a flat white plastic washer (rather than the rubber mounting grommet used with a flexible mounting leg). The bolt and washer must

be removed before the furnace is placed into operation. After the bolt and washer have been removed, the rig-

id leg will not touch the blower housing.

SL280DFV07036A WITH 1/2 HP

BLOWER MOTOR

RIGID LEG

remove shipping bolt and washer

FIBERGLASS SEALING STRIP (Field Provided)

CABINET SIDE

PANEL

FIGURE 10

4 − In closet installations, it may be impossible to install

sheet metal screws from the outside. In this case,

make plenum with a removable front and install

screws from the inside (See figure 10).

5 − Make certain that an adequate seal is made.

FIGURE 11

WARNING

The blower access panel must be securely in place when the blower and burners are operating. Gas fumes, which could contain carbon monoxide, can be drawn into living space resulting in personal injury or death.

Page 10

Front

Back

FIGURE 12 Downflow Application Allow for clearances to combustible materials as indicated on the unit nameplate. Minimum clearances for closet or alcove installations are shown in figure 13.

Downflow Application Installation Clearances

Top

Left Side

Bottom

Type of Vent

Connector

Top 1 in. (25 mm) 1 in. (25 mm)

*Front 2−1/4 in. (57 mm)** 2−1/4in. (57 mm)

Back 0 0

Sides 0† 0

Vent 6 in. (152 mm) 1 in. (25 mm)

Floor NC†† NC††

*Front clearance in alcove installation must be 24 in. (610 mm). Maintain a minimum of 24 in. (610 mm) for front service access. ** 3−1/4 in. if single wall vent pipe is used. †Left side requires 3 in. if a single wall vent is used on 14 −1/2 in. cabinets, or 2 in. if a single wall vent is used on 17 − 1/2 in. cabinets. ††The furnace may be installed on a combustible wood floor if an optional additive base is installed between the furnace and the combustible floor.

Type C Type B1

Right Side

FIGURE 13

Horizontal

WARNING

Improper installation of the furnace can result in personal injury or death. Combustion and flue products must never be allowed to enter the return air system or the living space. Use screws and joint tape to seal the return air system to the furnace. In platform installations with bottom return air, the furnace should be sealed airtight to the return air plenum. A door must never be used as a portion of the return air duct system. The base must provide a stable support and an airtight seal to the furnace. Allow absolutely no sagging, cracks, gaps, etc. The return and supply air duct systems must never be connected to or from other heating devices such as a fireplace or stove, etc. Fire, explosion, carbon monoxide poisoning, personal injury and/or property damage could result.

Filters

This unit is not equipped with a filter or rack. A field−provided high−velocity filter is required for the unit to operate properly. Table 3 lists recommended filter sizes. A filter must be in place any time the unit is operating.

TABLE 3

Cabinet Width

A (14−1/2") 14 x 25 x 1 (1) B (17−1/2") 16 x 25 x 1 (1)

C (21") 20 x 25 x 1 (1)

Return Air Filter Size (inches)

Page 11

Duct System

Use industry-approved standards (such as those published by Air Conditioning Contractors of America or American Society of Heating, Refrigerating and Air Conditioning Engineers) to size and install the supply and return air duct system. This will result in a quiet and low-static system that has uniform air distribution.

NOTE − Do not operate the furnace in the heating mode with an external static pressure that exceeds 0.8 inches w.c. Higher external static pressures may cause erratic limit operation.

Ensure that you have made a seal between the supply air plenum and the furnace and between the furnace and the return air plenum.

Return Air Plenum Return air must not be drawn from a room where this

furnace, or any other gas−fueled appliance (i.e., water heater), or carbon monoxide−producing device (i.e., wood fireplace) is installed. When return air is drawn

from a room, a negative pressure is created in the room. If a gas appliance is operating in a room with negative pressure, the flue products can be pulled back down the vent pipe and into the room. This reverse flow of the flue gas may result in incomplete combustion and the formation of carbon monoxide gas. This toxic gas might then be distributed throughout the house by the furnace duct system.

Venting

A 4−inch diameter flue transition is factory-installed on all models. Modifying or removing the flue transition will

cause the unit to operate unsafely and will void the unit certification. The vent connector does not require insula-

tion. The SL280DFV series units are classified as fan−assisted Category I furnaces when vertically vented according to the latest edition of National Fuel Gas Code (NFPA 54 / ANSI Z223.1). A fan−assisted Category I furnace is an appliance equipped with an integral mechanical means to either draw or force combustion products through the combustion chamber and/or heat exchanger.

NOTE − Use these instructions as a guide. They do not supersede local codes. This furnace must be vented according to all local codes, these installation instructions, and the provided venting tables in these instructions

The venting tables in this manual were extracted from the National Fuel Gas Code (NFPA 54 / ANSI Z223.1) and are provided as a guide for proper vent installation. Proper application, termination, construction and location of vents must conform to local codes having jurisdiction. In the absence of local codes, the NFGC serves as the defining document.

Refer to the tables and the venting information contained in these instructions to properly size and install the venting system.

IMPORTANT

Once the venting system is installed, attach the Disconnected Vent" warning sticker to a visible area of the plenum near the vent pipe. The warning sticker is provided in the bag assembly. Order kit 66W04 for additional stickers.

WARNING

Asphyxiation hazard. The exhaust vent for this furnace must be securely connected to the furnace flue transition at all times.

VENT CONNECTION

FLUE TRANSITION

COLLAR

FIGURE 14

Use self−drilling sheet metal screws or a mechanical fastener to firmly secure the vent pipe to the round collar of the flue transition. If self−drilling screws are used to attach the vent pipe, it is recommended that three be used. Drive one self−drilling screw through the front and one through each side of the vent pipe and collar. See figure 14.

Masonry chimneys used to vent Category I central furnaces must be either tile-lined or lined with a listed metal lining system or dedicated gas vent. Unlined masonry chimneys are prohibited. See figures 15 and 16 for common venting.

“DISCONNECTED VENT”

WARNING

STICKER

Page 12

Common Venting Using Tile−Lined Interior Masonry Chimney and Combined Vent Connector

MINIMUM LENGTH = AS SHORT AS PRACTICAL.

NOTE− Refer to provided venting

tables for installations.

FOR MAXIMUM LENGTH SEE NOTE TO LEFT

OTHER

APPLIANCE

FIGURE 15 Venting Using a Masonry Chimney

The following additional requirements apply when a lined masonry chimney is used to vent this furnace.

A chimney with one or more sides exposed to the outside of the structure is considered to be an exterior chimney.

An exterior masonry chimney that is not tile−lined must be lined with B1 vent or a listed insulated flexible metal vent. An exterior tile−lined chimney that is sealed and capped may be lined with a listed uninsulated flexible metal vent.

If the existing chimney will not accommodate a listed metal liner, either the chimney must be rebuilt to accommodate one of these liners or an alternate approved venting method must be found.

Insulation for the flexible vent pipe must be an encapsulated fiberglass sleeve recommended by the flexible vent pipe manufacturer. See figure 16.

Common Venting Using Metal−Lined Masonry Chimney

SEALED

MAX. LENGTH

−− SEE NOTE

5 ft. (1.5 m)

minimum

VENT CONNECTOR

4 in. (102 mm)

minimum

OTHER

APPLIANCE

NOTE 1 − Refer to the provided venting tables for installations.

BELOW.

MIN. LENGTH −− AS

SHORT AS PRACTICAL

FURNACE

EXTERIOR

CHIMNEY WITH

METAL

LINER

PERMANENTLY

SEALED FIREPLACE

OPENING

FIGURE 16

INTERIOR TILE−LINED MASONRY CHIMNEY

NOTE − the chimney must be properly sized per provided venting tables or lined with listed metal lining system.

VENT

CONNECTOR

FURNACE

PERMANENTLY SEALED FIREPLACE OPENING

DO NOT insulate the space between the liner and the chimney wall with puffed mica or any other loose granular insulating material

IMPORTANT

SINGLE appliance venting of a fan-assisted furnace into a tile-lined masonry chimney (interior or outside wall) is PROHIBITED. The chimney must first be lined with either type B1 vent or an insulated single wall flexible vent lining system which has been sized according to the provided venting tables and the vent pipe manufacturer’s instructions.

A fan−assisted furnace may be commonly vented into an existing lined masonry chimney if the following conditions are met:

 The chimney is currently serving at least one drafthood

equipped appliance

 The vent connectors and chimney are sized according

to the provided venting tables.

If type B1 double-wall vent is used inside a chimney, no other appliance can be vented into the chimney. The outer wall of type B1 vent pipe must not be exposed to flue products.

A type B1 vent or masonry chimney liner shall terminate above the roof surface with a listed cap or a listed roof assembly according to the terms of their respective listings and the vent manufacturer’s instructions.

When inspection reveals that an existing chimney is not safe for the intended purpose, it shall be rebuilt to conform to nationally recognized standards, lined or relined with suitable materials, or replaced with a gas vent or chimney suitable for venting SL280DFV series units. The chimney passageway must be checked periodically to ensure that it is clear and free of obstructions.

Do not install a manual damper, barometric draft regulator, or flue restrictor between the furnace and the chimney.

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Never connect a Category I appliance to a chimney that is servicing a solid−fuel appliance. If a fireplace chimney flue is used to vent this appliance, the fireplace opening must be permanently sealed.

A type B or listed chimney lining system that passes through an unused masonry chimney flue is not considered to be exposed to the outdoors.

General Venting Requirements

Vent all SL280DFV furnaces according to these instructions:

1 − Vent diameter recommendations and maximum allow-

able piping runs are found in the provided venting tables.

2 − In no case should the vent or vent connector diameter

be less than the diameter specified in the provided venting tables.

3 − The minimum vent capacity determined by the sizing

tables must be less than the low fire input rating and the maximum vent capacity must be greater than the high fire input rating.

4 − Single appliance vents − If the vertical vent or tile-lined

chimney has a larger diameter or flow area than the vent connector, use the vertical vent diameter to determine the minimum vent capacity and the vent

connector diameter to determine the maximum vent capacity. The flow area of the vertical vent, however,

shall not exceed 7 times the flow area of the listed appliance categorized vent area, drafthood outlet area or flue collar area unless designed according to approved engineering methods.

5 − Multiple appliance vents − The flow area of the largest

section of vertical vent or chimney shall not exceed 7 times the smallest listed appliance categorized vent area, drafthood outlet area or flue collar area unless designed according to approved engineering methods.

6 − The entire length of single wall metal vent connector

shall be readily accessible for inspection, cleaning, and replacement.

7 − Single appliance venting configurations with zero lat-

eral lengths (tables 5 and 6) are assumed to have no elbows in the vent system. For all other vent configurations, the vent system is assumed to have two 90° elbows. For each additional 90° elbow or equivalent (for example two 45° elbows equal one 90° elbow) beyond two, the maximum capacity listed in the venting table should be reduced by 10% (0.90 x maximum listed capacity).

8 − The common venting tables (7, 8, 9, and 10) were gen-

erated using a maximum horizontal vent connector length of 1−1/2 feet (.46 m) for each inch (25 mm) of connector diameter as follows:

TABLE 4

Connector Diameter

inches (mm)

3 (76) 4−1/2 (1.37)

4 (102) 6 (1.83)

5 (127) 7−1/2 (2.29)

6 (152) 9 (2.74)

7 (178) 10−1/2 (3.20)

Maximum Horizontal

Connector Length feet (m)

9 − If the common vertical vent is offset, the maximum

common vent capacity listed in the common venting tables should be reduced by 20%, the equivalent of two 90° elbows (0.80 x maximum common vent capacity). The horizontal length of the offset shall not exceed 1-1/2 feet (.46 m) for each inch (25 mm) of common vent diameter.

10 − The vent pipe should be as short as possible with the

least number of elbows and angles required to complete the job. Route the vent connector to the vent using the shortest possible route.

11 − A vent connector shall be supported without any dips

or sags and shall slope a minimum of 1/4 inch (6.4 mm) per linear foot (305 mm) of connector, back toward the appliance.

12 − Vent connectors shall be firmly attached to the furnace

flue collar by self−drilling screws or other approved means, except vent connectors of listed type B vent material which shall be assembled according to the manufacturer’s instructions. Joints between sections of single wall connector piping shall be fastened by screws or other approved means.

13 − When the vent connector used for Category I ap-

pliances must be located in or pass through a crawlspace or other areas which may be cold, that portion of the vent connector shall be constructed of listed double-wall type B vent material or material having equivalent insulation qualities.

14 − All venting pipe passing through floors, walls, and ceil-

ings must be installed with the listed clearance to combustible materials and be fire stopped according to local codes. In absence of local codes, refer to NFGC (Z223.1).

15 − No portion of the venting system can extend into, or pass

through any circulation air duct or plenum.

16 − Vent connectors serving Category I appliances shall

not be connected to any portion of mechanical draft systems operating under positive pressure such as Category III or IV venting systems.

17 − If vent connectors are combined prior to entering the

common vent, the maximum common vent capacity listed in the common venting tables must be reduced by 10%, the equivalent of one 90° elbow (0.90 x maximum common vent capacity).

Page 14

18 − The common vent diameter must always be at least as

large as the largest vent connector diameter.

19 − In no case, shall the vent connector be sized more than

two consecutive table size diameters over the size of the draft hood outlet or flue collar outlet.

20 − Do not install a manual damper, barometric draft regu-

lator or flue restrictor between the furnace and the

21 − When connecting this appliance to an existing dedi-

cated or common venting system, you must inspect the venting system’s general condition and look for signs of corrosion. The existing vent pipe size must conform to these instructions and the provided venting tables. If the existing venting system does not meet these requirements, it must be resized.

chimney.

TABLE 5

Capacity of Type B Double−Wall Vents with Type B Double−Wall Connectors

Serving a Single Category I Appliance

Vent and Connector Diameter − D (inches)

Height

(feet)

NOTE − Single appliance venting configurations with zero lateral lengths are assumed to have no elbows in the vent system. For all other vent configurations, the vent system is assumed to have two 90° elbows. For each additional 90° elbow or equivalent (for example two 45° elbows equal one 90° elbow) beyond two, the maximum capacity listed in the venting table should be reduced by 10 percent (0.90 x maximum listed capacity).

Lateral

(feet)

0 0 78 0 152 0 251 0 375

2 13 51 18 97 27 157 32 232

4 21 49 30 94 39 153 50 227

6 25 46 36 91 47 149 59 223

0 0 84 0 165 0 276 0 415

2 12 57 16 109 25 178 28 263

5 23 53 32 103 42 171 53 255

8 28 49 39 98 51 164 64 247

0 0 88 0 175 0 295 0 447

2 12 61 17 118 23 194 26 289

5 23 57 32 113 41 187 52 280

10 30 51 41 104 54 176 67 267

0 0 94 0 191 0 327 0 502

2 11 69 15 136 20 226 22 339

5 22 65 30 130 39 219 49 330

10 29 59 40 121 51 206 64 315

15 35 53 48 112 61 195 76 301

0 0 97 0 202 0 349 0 540

2 10 75 14 149 18 250 20 377

5 21 71 29 143 38 242 47 367

10 28 64 38 133 50 229 62 351

15 34 58 46 124 59 217 73 337

20 48 52 55 116 69 206 84 322

0 0 100 0 213 0 374 0 587

2 9 81 13 166 14 283 18 432

5 21 77 28 160 36 275 45 421

10 27 70 37 150 48 262 59 405

15 33 64 44 141 57 249 70 389

20 56 58 53 132 66 237 80 374

30 NR NR 73 113 88 214 104 346

3 Inch 4 Inch 5 Inch 6 Inch

Appliance Input Rating in Thousands of Btu Per Hour

MIN MAX MIN MAX MIN MAX MIN MAX

Page 15

TABLE 6

Capacity of Type B Double−Wall Vents with Single−Wall Metal Connectors

Serving a Single Category I Appliance

Vent and Connector Diameter − D (inches)

Height

(feet)

Lateral

(feet)

0 38 77 59 151 85 249 126 373

2 39 51 60 96 85 156 123 231

4 NR NR 74 92 102 152 146 225

6 NR NR 83 89 114 147 163 220

0 37 83 58 164 83 273 123 412

2 39 56 59 108 83 176 121 261

5 NR NR 77 102 107 168 151 252

8 NR NR 90 95 122 161 175 243

0 37 87 57 174 82 293 120 444

2 39 61 59 117 82 193 119 287

5 52 56 76 111 105 185 148 277

10 NR NR 97 100 132 171 188 261

0 36 93 56 190 80 325 116 499

2 38 69 57 136 80 225 115 337

5 51 63 75 128 102 216 144 326

10 NR NR 95 116 128 201 182 308

15 NR NR NR NR 158 186 220 290

0 35 96 54 200 78 346 114 537

2 37 74 56 148 78 248 113 375

5 50 68 73 140 100 239 141 363

10 NR NR 93 129 125 223 177 344

15 NR NR NR NR 155 208 216 325

20 NR NR NR NR 186 192 254 306

0 34 99 53 211 76 372 110 584

2 37 80 55 164 76 281 109 429

5 49 74 72 157 98 271 136 417

10 NR NR 91 144 122 255 171 397

15 NR NR 11 5 131 151 239 208 377

20 NR NR NR NR 181 223 246 357

30 NR NR NR NR NR NR NR NR

3 Inch 4 Inch 5 Inch 6 Inch

Appliance Input Rating in Thousands of Btu Per Hour

MIN MAX MIN MAX MIN MAX MIN MAX

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Vent

Height

(feet)

TABLE 7

Vent Connector Capacity

Type B Double−Wall Vents with Type B Double−Wall Connectors

Serving Two or More Category I Appliances

Connector

Rise

(feet)

1 22 37 35 66 46 106 58 164

2 23 41 37 75 48 121 60 183

3 24 44 38 81 49 132 62 199

1 22 40 35 72 49 114 64 176

2 23 44 36 80 51 128 66 195

3 24 47 37 87 53 139 67 210

1 22 43 34 78 49 123 65 189

2 23 47 36 86 51 136 67 206

3 24 50 37 92 52 146 69 220

1 21 50 33 89 47 142 64 220

2 22 53 35 96 49 153 66 235

3 24 55 36 102 51 163 68 248

1 21 54 33 99 46 157 62 246

2 22 57 34 105 48 167 64 259

3 23 60 35 110 50 176 66 271

1 20 62 31 113 45 181 60 288

2 21 64 33 118 47 190 62 299

3 22 66 34 123 48 198 64 309

3 Inch 4 Inch 5 Inch 6 Inch

MIN MAX MIN MAX MIN MAX MIN MAX

Vent and Connector Diameter − D (inches)

Appliance Input Rating in Thousands of Btu Per Hour

TABLE 8

Common Vent Capacity

Type B Double−Wall Vents with Type B Double−Wall Connectors

Serving Two or More Category I Appliances

Vent

Height

(feet)

6 92 81 140 11 6 204 161 309 248

8 101 90 155 129 224 178 339 275

10 110 97 169 141 243 194 367 299

15 125 112 195 164 283 228 427 352

20 136 123 215 183 314 255 475 394

30 152 138 244 210 361 297 547 459

FAN + FAN FAN + NAT FAN + FAN FAN + NAT FAN + FAN FAN + NAT FAN + FAN FAN + NAT

4 Inch 5 Inch 6 Inch 7 Inch

Appliance Input Rating in Thousands of Btu Per Hour

Common Vent Diameter − D (inches)

Page 17

Height

(feet)

TABLE 9

Vent Connector Capacity

Type B Double−Wall Vents with Single−Wall Metal Connectors

Serving Two or More Category I Appliances

Vent and Connector Diameter − D (inches)

Lateral

(feet)

1 NR NR NR NR NR NR NR NR

2 NR NR NR NR NR NR 168 182

3 NR NR NR NR 121 131 175 198

1 NR NR NR NR NR NA NR NR

2 NR NR NR NR 125 126 184 193

3 NR NR NR NR 130 138 191 208

1 NR NR NR NR 119 121 182 186

2 NR NR 84 85 124 134 189 203

3 NR NR 89 91 129 144 197 217

1 NR NR 79 87 116 138 177 214

2 NR NR 83 94 121 150 185 230

3 NR NR 87 100 127 160 193 243

1 49 56 78 97 115 152 175 238

2 52 59 82 103 120 163 182 252

3 55 62 87 107 125 172 190 264

1 47 60 77 110 112 175 169 278

2 51 62 81 115 117 185 177 290

3 54 64 85 119 122 193 185 300

3 Inch 4 Inch 5 Inch 6 Inch

Appliance Input Rating in Thousands of Btu Per Hour

MIN MAX MIN MAX MIN MAX MIN MAX

TABLE 10

Common Vent Capacity

Type B Double−Wall Vents with Single−Wall Metal Connectors

Serving Two or More Category I Appliances

Vent

Height

(feet)

6 NA 78 NA 11 3 200 158 304 244

8 NA 87 NA 126 218 173 331 269

10 NA 94 163 137 237 189 357 292

15 121 108 189 159 275 221 416 343

20 131 118 208 177 305 247 463 383

30 145 132 236 202 350 286 533 446

FAN + FAN FAN + NAT FAN + FAN FAN + NAT FAN + FAN FAN + NAT FAN + FAN FAN + NAT

4 Inch 5 Inch 6 Inch 7 Inch

Appliance Input Rating in Thousands of Btu Per Hour

Common Vent Diameter − D (inches)

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